Tama is located in the foothills of the Okutama Mountains of southwestern Tokyo, known as Tama Hills, which spans Tokyo and Kanagawa Prefecture. The entire region is historically referred to as Tama; therefore there are many place names scattered throughout the area with references to the name "Tama" which are not within the city limits. The Tama River marks the city's northern boundary, and Kanagawa Prefecture is to the south. Its southern half forms part of the Tama New Town project, Japan's largest residential development, constructed in the 1970s.